Improvement in the manufacture of artificial stone



I06. COMPOSITIONS,

If. .I

COATING OR PLASTIC.

UNITED STATES eueenrurlszqs g y Hammer PATENT OFFICE.

CHARLES J. BANDMAN, o -anuon, NEW JERSEY.

IMPROVEMENT IN THE MANUFACTURE OF ARTIFICIAL STONE.

Specification formin g part of Letters Patent No. 125,264, dated April 2, 1872.

I a plaster of common or fat} lime, in the propor ions na on -1 a s 1 pas e is obtained.

My process difl'ers from the ordinary process of making cement-stone, concrete, or bton, in that aport-ion of the sand and cement is replaced by iron-furnace slags, which in their composition are generally very similar to the Italian pozzuolanathe oldest known natural cement. The sla gs should contain from forty-five to fiftyfive per cent. of silica, and from ten to twenty per cent. of alumina. They should, however, only contain traces of iron and manganese, as any considerable quantity of these would prove injurious. Among the iron-furnace slags which I have found best adapted for my purpose, I will mention those having the composition of Wollastonite, diopside, Labradorite, chytophyllite, hornblende, and pilka-randit.

According to Bruno Kerl, (ride his Handbuch der Metallurgie, vol. 1, page 889,) the 1 last-mentioned sla is for instance composed *7 7 e of 46.88 I1 8 silicaalumi 1.48 oxide of man 'anese' 148 ma nesia. Such sIags are ffl' orme in most yet they may i, be replaced by other iron slags, even if they are not exactly of the above description.

Since iron slags of the given composition are eificient pozzuolanas of themselves, and since they constitute a refuse material to be had in almost every section of this country, I am enabled to produce by their use a tar cheaper artificial stone, and one equally strong and durable with that which is generally produced by a mere mixture of hydraulic limes and sand. To produce my stone, which I propose to call Zeolite Artificial Stone because it resembles the natural zeolite, I first take the iron sla of the quality above described, whicltmsing, is re ce r liable owder by grinding or s1 mg, and mix ns pow er with This mixture is then compounded with sand or other inert material, and when each par 1- cle of the latter is coated all over with a film of this matrix, and the mass thoroughly incorporated together, I then add thereto hydraulic .lime in-the proportion of about one-eigi o the Bulk of the compounded mass.

For mixing I use the common mortar-box, if for small quantities, and for large masses a pug-mill.

.To produce ornamental work I form molds of plaster of Paris, which may be coated with a solution of shellac to prevent the plaster from adhering to the freshly-made composition.

For large blocks, and'those of plain surface, molds may be made of wood or other suitable material.

I am aware that iron-furnace sla gs have been employed for making artificial stone; but they were not reduced to a finely-powdered stateneither were they mixed with slacked lime before being incorporated with other materials;

hence no cement of any hydraulic energy was obtained. 'If, for instance, the lime is mixed with the cement which it is proposed to employ, and the slag powder introduced afterward, a greatly inferior product is obtained.

I also propose to use only slags which are similar in their chemical composition to Italian pozzuolanas.

What I claim as my invention is- An artificial stone formed by the process of mixing slaked lime with finely-powdered iron witnesses.

CHARLES J. BANDMAN. Witnesses:

. A. J. CRAWFORD,

, GEO. W. MIATT. 

